At the present time, in accordance with the known art, necessary measures and controls are accomplished by means of empirical methods using traditional measuring instruments such as scales, goniometers and the like. Therefore the valuations and data thus obtained greatly depend on the capability of the operator and accuracy of measurements.
It is known that in the particular field of motor-vehicles the control of the characteristic spots and areas in motor-vehicle bodies is carried out by the use of suitable reforming and straightening apparatus. Such controls, although sufficiently precise, do however require hard measurings and rather long execution times. It is also to be noted that with the use of traditional reforming and straightening apparatus it is not possible to define the spatial configuration but only to check the location of the characteristic spots in the structure compared with already known reference positions.
As to the particular case concerning the control of the trim of the wheels, it is presently carried out, as is known, by the use of specific optical-mechanical apparatus quite differentiated from the above mentioned systems for the control of the bodies.